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1.
Nat Commun ; 13(1): 640, 2022 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-35110575

RESUMEN

Magnetic reconnection is a multi-faceted process of energy conversion in astrophysical, space and laboratory plasmas that operates at microscopic scales but has macroscopic drivers and consequences. Solar flares present a key laboratory for its study, leaving imprints of the microscopic physics in radiation spectra and allowing the macroscopic evolution to be imaged, yet a full observational characterization remains elusive. Here we combine high resolution imaging and spectral observations of a confined solar flare at multiple wavelengths with data-constrained magnetohydrodynamic modeling to study the dynamics of the flare plasma from the current sheet to the plasmoid scale. The analysis suggests that the flare resulted from the interaction of a twisted magnetic flux rope surrounding a filament with nearby magnetic loops whose feet are anchored in chromospheric fibrils. Bright cusp-shaped structures represent the region around a reconnecting separator or quasi-separator (hyperbolic flux tube). The fast reconnection, which is relevant for other astrophysical environments, revealed plasmoids in the current sheet and separatrices and associated unresolved turbulent motions.

2.
Nat Commun ; 7: 11837, 2016 06 16.
Artículo en Inglés | MEDLINE | ID: mdl-27306479

RESUMEN

Magnetic reconnection is a fundamental process of topology change and energy release, taking place in plasmas on the Sun, in space, in astrophysical objects and in the laboratory. However, observational evidence has been relatively rare and typically only partial. Here we present evidence of fast reconnection in a solar filament eruption using high-resolution H-alpha images from the New Vacuum Solar Telescope, supplemented by extreme ultraviolet observations. The reconnection is seen to occur between a set of ambient chromospheric fibrils and the filament itself. This allows for the relaxation of magnetic tension in the filament by an untwisting motion, demonstrating a flux rope structure. The topology change and untwisting are also found through nonlinear force-free field modelling of the active region in combination with magnetohydrodynamic simulation. These results demonstrate a new role for reconnection in solar eruptions: the release of magnetic twist.

3.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 16(5): 997-1001, 2008 Oct.
Artículo en Chino | MEDLINE | ID: mdl-18928582

RESUMEN

The purpose of this study was to investigate 135 cases of chronic myelogenous leukemia with non-simple Philadelphia chromosome and to analyze their cytogenetic date. Chromosome preparations in 135 cases of patients were performed by using direct method and/or short-term culture, and karyotyping was performed with R-banding technique. The results showed that the overall frequency of chronic myelogenous leukemia with non-simple Philadelphia chromosome (based on 1210 cases of chromosome detection in chronic myelogenous leukemia) was 11.16%, which included 87 cases of chronic phase, 21 cases of accelerated phase and 27 cases of blastic phase. Among 87 cases of patients in chronic phase, 14 cases were with simple variant translocation and 22 cases had complex variant translocation while the others were with other chromosomal abnormalities including 4 cases of +8, 4 cases of + Ph and 2 cases of i (17); among 21 cases of patients in accelerated phage, 4 cases were with +8 and 4 cases were with + Ph while 3 cases were with i (17); among 27 cases of patients in blastic phage, 2 cases were with simple variant translocation and 3 cases had complex variant translocation while the others were with other chromosomal abnormalities including 5 cases of +8, 5 cases of + Ph and 2 cases of i (17). The detection rate of extra chromosomal abnormalities in this group of 135 cases patient were + Ph, +8, i (17), -Y, +19 and +21 in order. There were 16 cases with simple variant translocation and 25 cases with complex variant translocation in in this group of 135 cases. It is concluded that karyotype analysis is helpful in diagnosis, prognosis, pathogenesis and treatment selection for chronic myelogenous leukemia.


Asunto(s)
Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Cromosoma Filadelfia , Adolescente , Adulto , Anciano , Niño , Femenino , Humanos , Cariotipificación , Masculino , Persona de Mediana Edad , Adulto Joven
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